class_docstr: Unit tests for the generate python code prompt class
code: def test_custom_instructions(self):
      custom_instructions = """Analyze the data.
  1. Load: Load the data from a file or database
  2. Prepare: Preprocessing and cleaning data if necessary
  3. Process: Manipulating data for analysis (grouping, filtering, aggregating, etc.)
  4. Analyze: Conducting the actual analysis (if the user asks to plot a chart you must save it as an image in temp_chart.png and not show the chart.)"""  # noqa: E501
  
      prompt = GeneratePythonCodePrompt(
          custom_instructions=custom_instructions
      )
      actual_instructions = prompt._args["instructions"]
  
      assert (
          actual_instructions
          == """Analyze the data.
  1. Load: Load the data from a file or database
  2. Prepare: Preprocessing and cleaning data if necessary
  3. Process: Manipulating data for analysis (grouping, filtering, aggregating, etc.)
  4. Analyze: Conducting the actual analysis (if the user asks to plot a chart you must save it as an image in temp_chart.png and not show the chart.)"""  # noqa: E501
      )
  
file_path: pandas-ai/tests/prompts/test_generate_python_code_prompt.py
imports: import sys
  import pandas
  import pytest
  from pandasai import SmartDataframe
  from pandasai.helpers.output_types import output_type_factory, DefaultOutputType, output_types_map
  from pandasai.prompts import GeneratePythonCodePrompt
  from pandasai.llm.fake import FakeLLM
  from pandasai.helpers.viz_library_types import MatplotlibVizLibraryType, viz_lib_map, viz_lib_type_factory
label_desc: Use image node_id 2 for calling the TestGeneratePythonCodePrompt obj's underlying member method code with example usage: obj.test_custom_instructions() without return types